Concrete (63) PROFICIENCY TESTING PROGRAM REPORT

Transcription

1 Concrete (63) PROFICIENCY TESTING PROGRAM REPORT Accredited for compliance with ISO/IEC Copyright: LabSmart Services Pty Ltd Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 1 of 37

2 Report This report is available on the LabSmart Services website. The issue of this proficiency report was authorised by Peter Young, Director, LabSmart Services Pty Ltd, June Contact Details Mobile: Fax: (03) Program Coordinator The program coordinator for this program was Peter Young, Director, LabSmart Services Pty Ltd. Contact Details Mobile: Fax: (03) Please note that any technical questions regarding this program are to be directed to the program coordinator. Z-scores Summary A z-scores summary for this program was issued in 6 April This technical report supersedes the z-sores summary. Accredited Proficiency Testing Provider LabSmart Services is accredited by NATA to ISO/IEC 17043, Conformity assessment General requirements for proficiency testing. Accreditation number The accreditation provides additional assurance to participants of the quality and importance we place on our proficiency testing programs. LabSmart Services As well as proficiency testing programs LabSmart Services also offers nuclear gauge calibration. Please see our website for further details. Copyright This work is copyright. No part of this publication may be reproduced in any form, transmitted or stored in any repository (e.g. mechanical, digital, electronic or photographic) without prior written permission of LabSmart Services Pty Ltd. Please contact LabSmart Services should you wish to reproduce any part of this report. Amendment History Reports may be downloaded from the LabSmart Services website. Version 1 Issued 19 June 2016 Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 2 of 37

3 CONTENTS PAGE 1. Proficiency Program Aim 4 2. Performance 2.1 Identified Outliers 2.2 Overall Performance 3. Technical Comment 3.1 Compression Strength 3.2 Mass per Unit Volume 3.3 Intermediate Parameters 4. Statistics: Z-Scores & Graph 4.1 Sample A - Compressive Strength 4.2 Sample A - Mass per Unit Volume 4.3 Sample B - Compressive Strength 4.4 Sample B - Mass per Unit Volume 5. Program Details 5.1 Z-score Summary 5.2 Program Design 5.3 Sample Preparation 5.4 Packaging and Instructions 5.5 Quarantine 5.6 Sample Dispatch 5.7 Homogeneity Testing 5.8 Participation 5.9 Statistics Summary of Participant s Results 6.1 Sample A 6.2 Sample B Appendix A Statistics - Intermediate Parameters Appendix A - Notes A-1 Height A-2 Average Diameter A-3 Weight A-4 Maximum Force Appendix B Instructions for testers Appendix C Results Log Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 3 of 37

4 1. Program Aim The proficiency program was conducted in March The program involved the performance of: AS , Determination of the compressive strength of concrete specimens and AS (R2014), Determination of mass per unit volume. The program provides feedback and confidence to the construction materials testing industry regarding the competency of participants (and the industry) to perform these tests. Each participant s performance is statistically assessed and used as a measure of competency relative to all those who participated. A Z-score summary was issued to participants on the 6 April to facilitate early feedback. This report has been prepared using a robust statistical approach. In addition, data has been reviewed for consistency and additional feedback regarding aspects of the test are provided. Comprehensive technical comment is provided to assist participants improve the overall performance of this test. 2. Performance 2.1. Identified Outliers Overall a satisfactory level of testing was achieved by the majority of participants, most not listed below had z-scores between -1 and 1 which is considered an excellent result. Outliers were classified as z-scores where the absolute z-score value was greater than 3. There were two participants (5%) with outliers. Participants obtaining a z-score outside the range ± 2 may wish to consider reviewing their results. See table 2.1-A below. Please note that only those participants with an absolute z-score great than 2.75 are shown in the review column. Participant s z-scores and graphs are detailed in section 4. Test Investigate (Outliers) Review Sample A Sample B Sample A Sample B Mass per unit volume Compressive strength S5, Z9 S5 - - Table 2.1-A Statistical Outliers Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 4 of 37

5 It is recommended that participants consult the technical comment section (3) of this report. Some other participants whose results may not have shown as an outlier may need to investigate the result obtained. See table 2.1-B below. Test Investigate Review Sample A Sample B Sample A Sample B Mass per unit volume M8 M8 T4 - Compressive strength Overall Performance Table 2.1-B Results requiring further investigation or review The overall performance by the vast majority of participants (95%) was very good. The spread of results (Variation) was well within industry expectations. Both sample A and B gave an approximate standard deviation of 2 MPa. There were 40 participants in the program all of whom returned results. Sample A Sample B Statistic Compressive Strength Mass per unit volume Compressive Strength Mass per unit volume MPa kg/m 3 MPa kg/m 3 No of participants Median N-IOR CV (%) Range * Table 2.2 Summary of test results statistics. Range* excludes outlier results. Some statistics have been rounded. The compressive strength results for both Sample A and Sample B showed a very small variation. The mass per unit volume results were within the expected variation for this test. The outcome was consistent with previous proficiency programs. Overall the results are well within industry expectations and demonstrated that the majority of participants were competent in performing these tests. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 5 of 37

6 3. Technical Comment General A summary of results for all participants may be found in section 6. The reporting requirements under the Australian Standard are compressive strength and mass per unit volume. Outlier assessment was undertaken based on these results, the robust statistical analysis of these can be found in section 4 of this report. Appendix A details some statistics which may be useful in investigating any follow up action. Outcome Overall there was very good agreement amongst participants for both the Mass per Unit Volume and the Compressive Strength. The overall program statistics are similar to those obtained in previous programs. The coefficient of variation (CV) shown in table 3-A is one way to broadly observe that participant performance is consistent from one program to another. That is the CV values are roughly in the same ballpark. It should be noted that the actual fluctuation in CV values may be attributed to a range of factors. As a consequence, very little other information can be gained from the fluctuations observed. See section 5.9 for further details. Coefficient of Variation (%) Program Sample Mass per Unit Volume Compressive Strength 2016(63) 2014(56) 2013(43) 2012(38) 2012(34) 2012(29) 2010(17) 2008(5) A B A B A B A B A B A B A B A B Table 3-A Summary of CV for current and past programs Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 6 of 37

7 Missing Information Compared to previous programs everyone provided the information requested on the results log sheet except participant D5. Thank you to all participants as this makes it far easier to provide informative feedback. 3.1 Compressive Strength Calculation of compressive strength From the reported diameter and maximum force, the Compressive Strength results can be determined. This was done for each result and compared to the reported compressive strength. Good agreement was obtained for all participants except for participant T4, Sample B. The difference was only 0.8 MPa but it may be worthwhile reviewing this result. Statistical Outliers Participant S5 reported low compressive strength results and low crushing force results for sample A & B that showed as outliers in the program. The failure mode for Sample A was Shear Failure while for sample B, Conical Failure. A rubber cap was used. There appears, from participants results, little correlation of failure mode to the compressive strength obtained. A range of photos was provided but did not indicate any particular issue. Centring of the specimens on the platens appeared fine. Wear of capping used may need to be checked. The specimen showed no significant variations physically. The mass per unit volumes for both samples were fine. Appendix A showed no significant variation except for the force results obtained. Participant Z9 reported a low compressive strength result and low crushing force result for sample A that showed as an outlier in the program. The cylinder was rubber capped. The failure mode was noted as conical failure. As discussed above the mode of failure is unlikely to have caused the low results. There may have been an issue with the platens, centring of the specimens on the platens or handling/preparation of the test specimens. The specimen showed no significant variation in the mass per unit volume. Appendix A showed no significant variation except for the force result obtained for sample A. Variation in compressive strength AS provides some guidance with regards to the expected within laboratory precision of testing. It indicates that 2 cylinders tested at 28 days should be repeatable within 10% of the mean at a 95% probability level. The proficiency program looks at the variation over a number of laboratories and the above precision is not applicable. However, the between laboratory variation would be expected to be greater than the within laboratory precision detailed above. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 7 of 37

8 The 10% precision estimate is still however useful for interpreting the outcome of the program. See table 3.1-A. Statistic Sample A Sample B Median Within laboratory variation estimate (10% of median) Between laboratory variation (SD x 2) Table 3.1-A Comparison of predicted and observed variation Table 3.1 indicates that variation is comparable between the precision expected (i.e. of two cylinders tested within the same laboratory) to the variation observed for all the participants. The NIQR is an estimate of the SD and equates to a z- score of 1. It is reasonable to conclude that, with most participant s results under 1 S.D and all fell under 2 SD, that all participants are well within industry expectations (apart from participants with outliers). Failure Modes Around 30 % (12 sample A and 10 sample B) reported either cap or shear failure during crushing. Table 3.1-B are z-score based statistics for normal only and abnormal only compression results. Compression Statistic MPa Sample A Sample B Normal conical failure results only Median Estimated SD Number Compression Statistic MPa Sample A Sample B Normal conical failure results only Median Estimated SD Number Table 3.1-B Comparison of Conical and Shear/Cap failure results The spread of results of those showing an abnormal failure was not much different to those showing normal failure. There is no strong evidence to suggest that Shear failure or Cap values should be discounted or excluded from the data set. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 8 of 37

9 Equipment configuration, air voids, variability in compaction and aggregate distribution are only some of the factors that affect the mode of failure. Possible causes of abnormal failures might include capping and crushing practices, stability of the load frame (i.e. alignment, squareness and rigidity) as well as the correct working/alignment of platens. Participants (V7, J5, D5, W7, P6 & M8) that had abnormal failure for both sample A and B may benefit from rechecking equipment. The effect the mode of failure has on the compressive strength result is difficult to determine except in obvious instances where an unrealistically low result is obtained. Late crushing Cylinders were cured past 28 days prior to testing, so limited strength gain would be expected if cylinders were tested late. There were only three participants (V5, B8 & C5) that did not test on the nominated date of 11 March. Two were only a few days later on the 14 th while one was 18 days later on the 18 th. All results were higher of the median values. The z-scores were recalculated without these results and the median value for sample A & B remained the same. Other statistics were essentially the same resulting in the same outliers for the program being obtained. Capping Methods 27 participants used rubber caps (67%) with 6 participants (15%) using sulphur capping. There were 7 (18%) participants that cut the end. The following compressive strength statistics were recalculated for both sample A and B: Sulphur capping only Rubber capping only End-cut only End-cut and Sulphur only Due to the relative small numbers it is difficult to statistically evaluate. Based on the average or median values there was little difference between the various end preparations used. Previous proficiency programs have not encountered any adverse correlation between reported compressive strength and capping method. For this program rubber caps, sulphur capping and end-cut were considered to yield equivalent results and were analysed as a group. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 9 of 37

10 3.2 Mass per unit volume Rejected results Participant M8 results for unit volume for both sample A and B were rejected as not being realistic values for the test. The result was not included in the statistical evaluation but does need to be investigated. See also table 2.1-B. Calculation of mass per unit volume From the reported height, diameter and weight the mass per unit volume result can be determined. All participants mass per unit volume results were recalculated based on the intermediate data supplied (see Appendix A). This was done for each result and compared to the reported mass per unit volume. Generally good agreement was obtained. Some participants reported results that may have been rounded to the nearest 20 kg/m 3. For these participant s feedback is not possible. Recalculated results that differed by more than 10 kg/m 3 may require further review by participants. One participant (T4) detailed below was outside the 10 kg/m 3 limit set and may find it beneficial to review the results submitted. Sample A Sample B Submitted Recalculated Submitted Recalculated T B Z R K L The test method requires mass per unit volume result to be rounded to the nearest 20 kg/m 3. In many of the cases shown above the difference may not have an impact on the result reported. Other times it can affect the rounding and could be 20 kg/m 3 out. It is important that the calculation process is correct and accurate. Instructions on the calculation can be found in Section 8 of AS It states that the mass per unit volume is the mass divided by the cylinder volume. The volume of a cylinder is given by V= πhr 2 where h is the cylinder height and r is the average radius, (i.e. Half the average diameter). Measurements should be in meters to achieve the reported MPUV in kg/m 3. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 10 of 37

11 Unrounded values for diameter and height should be used when calculating the volume. The value of pi used can also have an effect. Those using excel can use the pi() function. Those with calculators that do not have a pi function should use 333/106. The use of 22/7 does not have sufficient accuracy. Statistical Outliers There were no statistical outliers for mass per unit volume. Reporting of cylinder weights Some participants cylinder weights were reported in grams instead of kg (see section 6). Converted values are shown in section 6 of the report. Participants need to ensure they follow proficiency program instructions. Conversions were undertaken as these values were used to verify the participants reported MPUV results. 3.3 Intermediate parameters There are a number of intermediate parameters which are measured in order to be able to calculate the mass per unit volume and compressive strength. The intermediate parameters are height, diameter, weight and maximum force. As the intermediate parameters are not required to be reported by the test method and may vary due to allowable variations in the concrete cylinders (moulds) they are not considered statistically as part of the proficiency program. This information however may prove useful where an outlier result occurs for mass per unit volume and/or compressive strength. For this reason, analysis of these intermediate parameters has been included in Appendix A-1 (height), A-2 (average diameter), A-3 (weight) and A-4 (maximum force). Appendix A is provided for information only. The z-scores are provided as an aid to assist with identifying possible issues and their resolution. Any outliers shown are for information only and do not need to be investigated. The values reported for height and diameter show a smaller spread (variation) than the test method tolerances might suggest would be achieved. This adds confidence that high quality proficiency testing cylinders were produced. Only one participant did not submit some intermediate results. Overall the performance by participating laboratories with respect to the intermediate results was good. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 11 of 37

12 4.1 Sample A - Compressive Strength: Z - Scores Test Result MPa Z Score Test Result MPa Z Score Z Y N Z # R Q V J L C J J V Q K L T M E R S B A U N P B D Z W N S # P K M X M A T Q Statistic Value Number of results 40 Median 42.1 Median MU 0.41 First Quartile Third Quartile IQR 2.80 Normalised IQR 2.08 CV (%) 4.9 Minimum 38.0 (34.4) Maximum 45.0 (45.0) Range 7.0 (10.6) Note: A # indicates an outlier where the z-score obtained is either greater then 3 or less than -3. s for all participates are shown. The results column shows a blank entry for those participants that did not submit a result for this test. Minimum, Maximum and Range are calculated with outliers excluded, those in brackets include outliers. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 12 of 37

13 4.1 Sample A - Compressive Strength: Z - Score Graph S5 Z9 E9 Q4 A5 K6 N3 T8 J2 N6 T4 M4 R4 P6 J5 D5 X9 Z2 Z7 L2 N2 M6 V7 B8 Q3 L6 R5 A3 M8 S6 P3 Y2 V9 K2 J9 W7 B3 C5 Q8 U Z-score Review Weak Consensus Strong Consensus Weak Consensus Review Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 13 of 37

14 4.2 Sample A - Unit Volume: Z - Scores Test Result Z Score kg/m 3 Test Result kg/m 3 Z Score Z Y N Z R Q V J L C J J V Q K L T M8 E R S B A U N P B D Z W N S P K M X M A T Q Statistic Value Number of results 39 Median 2334 Median MU 3.7 First Quartile 2320 Third Quartile 2345 IQR 25.0 Normalised IQR 18.5 CV (%) 0.8 Minimum 2290 () Maximum 2377 () Range 87 () Note: A # indicates an outlier where the z-score obtained is either greater then 3 or less than -3. s for all participates are shown. The results column shows a blank entry for those participants that did not submit a result for this test. Minimum, Maximum and Range are calculated with outliers excluded, those in brackets include outliers. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 14 of 37

15 4.2 Sample A - Unit Volume: Z - Score Graph Q3 V7 T4 Y2 M6 T8 Z7 E9 R4 L6 W7 J5 N3 P3 A5 N2 S6 S5 K2 B3 C5 V9 U4 J2 N6 P6 Q8 K6 A3 D5 X9 Q4 J9 Z9 Z2 M4 B8 L2 R Z-score Review Weak Consensus Strong Consensus Weak Consensus Review Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 15 of 37

16 4.3 Sample B - Compressive Strength: Z - Scores Test Result MPa Z Score Test Result MPa Z Score Z Y N Z R Q V J L C J J V Q K L T M E R S B A U N P B D Z W N S # P K M X M A T Q Statistic Value Number of results 40 Median 42.3 Median MU 0.41 First Quartile Third Quartile IQR 2.80 Normalised IQR 2.08 CV (%) 4.9 Minimum 39.9 (35.7) Maximum 45.6 (45.6) Range 5.7 (9.9) Note: A # indicates an outlier where the z-score obtained is either greater then 3 or less than -3. s for all participates are shown. The results column shows a blank entry for those participants that did not submit a result for this test. Minimum, Maximum and Range are calculated with outliers excluded, those in brackets include outliers. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 16 of 37

17 4.3 Sample B - Compressive Strength: Z - Score Graph S5 J2 A5 V7 V9 D5 A3 W7 J9 K6 R4 K2 Q4 B3 N3 T4 Q3 Y2 Q8 L2 P3 B8 M6 T8 R5 E9 M8 L6 P6 N2 Z2 J5 X9 S6 M4 N6 Z9 C5 Z7 U Z-score Review Weak Consensus Strong Consensus Weak Consensus Review Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 17 of 37

18 4.4 Sample B - Unit Volume: Z - Scores Test Result Z Score kg/m 3 Test Result kg/m 3 Z Score Z Y N Z R Q V J L C J J V Q K L T M8 E R S B A U N P B D Z W N S P K M X M A T Q Statistic Value Number of results 39 Median 2338 Median MU 2.8 First Quartile 2329 Third Quartile 2348 IQR 19.0 Normalised IQR 14.1 CV (%) 0.6 Minimum 2307 () Maximum 2361 () Range 54 () Note: A # indicates an outlier where the z-score obtained is either greater then 3 or less than -3. s for all participates are shown. The results column shows a blank entry for those participants that did not submit a result for this test. Minimum, Maximum and Range are calculated with outliers excluded, those in brackets include outliers. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 18 of 37

19 4.4 Sample B - Unit Volume: Z - Score Graph T8 Y2 P3 X9 A5 Q3 L6 E9 R4 B3 J5 V9 M4 M6 V7 Z2 Z7 K6 S6 N6 C5 B8 Z9 N3 W7 J2 A3 Q4 L2 P6 U4 Q8 N2 K2 R5 D5 S5 T4 J Z-score Review Weak Consensus Strong Consensus Weak Consensus Review Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 19 of 37

20 5. Program Details 5.1. Z - score Summary The proficiency program was conducted in March A Z-score Summary summary was issued on the 6 April 2016 and posted on the LabSmart Services web site. A copy was also ed to participants. The summary is intended as an early indicator of participant performance. This program report supersedes the z - score summary. Further information can be found in section 5.9 Statistics Program Design Design The program is held annually. Two concrete cylinders are required to be tested. The cylinders may be matched (same strength) or unmatched in strength (different strengths). The compressive strength also changes from year to year. The test requires a minimum skill level. Adherence to the test method is essential for consistent test results. Participant results are checked where possible. It is expected that the level of experience/skill needed to perform these tests will present a reasonable assessment of the overall competency of the tester and industry performance. The program was designed to provide technical feedback regarding performance as well as possible improvements in performance. Other considerations involving the design of the program are detailed below. Role of Proficiency Testing The determination of outliers is an important task of this proficiency program. A secondary function is to provide feedback that can help those with outliers identify possible areas to investigate as well as assist all participants to improve. In addition to the statistics, proficiency programs often obtain other information that is not normally available to a laboratory. It allows for a better understanding of the testing and can provide information that can lead to improvements in the testing process or test method. Proficiency testing enables participants to measure competency against others. It is also a measure of staff performance and the equipment used. Apart from measurement uncertainty it is the most useful tool a laboratory has in better understanding the performance of a test. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 20 of 37

21 Participant Assessment Assessment of each participant is based on a z-score that is related to the program consensus value (median) and compliance to proficiency program requirements including the correct calculation of results. Cylinder Production The concrete cylinders used for this program are made specifically for the program under controlled conditions to ensure uniformity in the strength of the cylinders provided. Reporting of Results - Significant Figures The number of decimal places (significant figures) reported for a test has a bearing on the statistical analysis and therefore the interpretation of the results. There is a need to strike a balance between what is desirable from a statistical viewpoint while recognising how the results are used in practice. Too few decimal places (e.g. due to rounding) can cause an increase in the observed spread of results. Increasing the number of decimal places (with respect to normal reporting) can distort the observed spread of results compared to that encountered in actual practice. Large numbers of similar, rounded results can also cause a distortion in the analysis. For example, rounding to 0.5 % means that any number between and will be 11.0%. If the largest value is in a set of results it is pushed out to 11.0 through rounding. Rounded results are useful from an end user perspective but are not as useful when considering laboratory performance. Some test methods acknowledge that additional decimal places may be used for statistical purposes. For this program it was decided that the benefits of using additional decimal places would complement the aim of the proficiency program. Participants results were analysed as received regardless of whether rounding had been done or that there were more or less significant figures than the number requested by the program. Additional Information Requested Most programs request additional information to that normally required to be reported by the test method. The additional information is however consistent with the performance of the test and the records the test method requires laboratories to maintain. The additional information is used to interpret participant s performance and assist with providing technical comment including feedback on outliers and possible participant improvement. The additional information is tabulated in Appendix A to the report and referenced in section 3 covering technical feedback. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 21 of 37

22 Data Checks The determination of outliers is an important task of this proficiency program. A secondary function is to provide feedback that can help those with outliers identify possible areas to investigate as well as assist all participants to improve. This information also helps with identifying any random or systematic errors associated with the test methodology. As observed in other proficiency programs operator errors often creep into the result calculation process. Assessment of participant s data was incorporated into this program to ensure data was comparable. Unit mass results were also recalculated based on the data provided Sample Preparation Two batches of concrete (A & B) were prepared using the same mix design. For each batch there were approximately 50 cylinders cast of nominal 40 MPa concrete. Cylinders were prepared, cast and cured as per the test standard. Each cylinder was individually numbered. Eight cylinders from each batch were selected for homogeneity testing. Samples were selected at evenly spaced intervals throughout the production process. A total of 16 samples were submitted for homogeneity testing. On removal from the curing tank each cylinder was wrapped in paper and double sealed in two plastic bags. One batch was marked as Sample A and the other Sample B. Samples were drawn at random from each batch to make a pair. Each pair of cylinders was assigned a unique participant code Packaging and Instructions Each pair of cylinders was placed into a sturdy box with bubble wrap. The boxed samples weighed approximately 5 kg. Instructions and a results log sheet were enclosed. (See Appendix B & C) 5.5. Quarantine There were no samples that required additional preparation in order to meet quarantine requirements Sample Despatch Samples were dispatched via courier. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 22 of 37

23 5.7. Homogeneity Testing Samples for homogeneity testing were packed in the same way as those for participants. The homogeneity samples were tested by an independent NATA accredited laboratory. To approximate the same conditions as participants the same instructions were given to the homogeneity laboratory. Homogeneity samples were tested prior to 28 days with sample A tested on a different compression machine to that used for Sample B. Analysis of the homogeneity testing results (Table 5.7) indicated that the variability associated with the proficiency samples was satisfactory. This provides confidence that any outliers identified in the program represent statistically valid outliers. Sample A Sample B Compressive Strength Mass per Unit Volume Compressive Strength Mass per Unit Volume MPa kg/m 3 MPa kg/m 3 H H H H H H H H Mean Standard Deviation Range Coefficient of Variation (%) Table 5.7 Homogeneity results Participation Forty participants from around Australia entered the program. Forty participants returned results Statistics Z-Scores were calculated and used to assess the variability of each participant relative to the consensus median. A corresponding z-score graph was produced for each test. See section 4. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 23 of 37

24 The use of median and quartiles reduces the effect that outliers have on the statistics and other influences. As a consequence z-scores provide a more realistic or robust method of assessment. Some results were reported by participants to more decimal places than requested as part of the proficiency program and by others to fewer decimal places. In all instances test results have been used as submitted by participants. Checks were undertaken to ensure the data calculated matched that reported by the participant and that the appropriate corrections had been applied if required. If inconsistencies were identified the data was removed but the discrepancy highlighted. A z-score is one way of measuring the degree of consensus with respect to the grouped test results. The z-scores in this report approximates the standard deviation. For each test a z-score graph is shown. Use the graph to visually check statistically how you compare to other participants. The following bar (Figure 5.9) is shown at the bottom of each graph. This helps to quickly visualize where each participant s results falls. Review Weak Consensus Strong Consensus Weak Consensus Review For example: Figure 5.9 Z-score interpretation bar A strong consensus (i.e. agreement) means that your test result is close i.e. within 1 standard deviation of the median. A weak consensus means that your test result is satisfactory and is within 2 standard deviations of the median. If you have obtained a test result that is outside 2 standard deviations then it may be worth reviewing your testing processes to ensure that all aspects are satisfactory. Only those obtaining a z-score approaching 3 (I.e. outside 2.75 range) have been highlighted in the report for review. If you have obtained a test result that is outside 3 standard deviations then you will need to investigate your testing processes to ensure that all aspects are satisfactory. For further details on the statistics used in this proficiency program can be obtained from LabSmart Services or download the Participant Guide from the LabSmart Services website. Z-score Summary A Z-Scores Summary is issued soon after the majority of results are received. It gives participants early feedback as to any program outliers. The summary is available on the LabSmart Services website up until the final report is issued. The final report supersedes the z-score summary. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 24 of 37

25 The final report contains detailed technical feedback regarding the performance of tests and revised z-scores. The inclusion of late results or corrections are at the discretion of the program coordinator. In some instances, this may change some of the z-scores slightly but generally the performance outcome remains the same. Any impact is discussed within section 3 of the report. Comparing statistics from one proficiency testing program to another The statistics generated from one proficiency program are not usually compared against those from another proficiency testing program. Only very general comparisons may be possible. The reason statistics from one program may not be compared to another is due to the range of variables that differ from one proficiency program to another. These variables include: Type of material selected, The number of participants, Experience of participants, Test methodology variations, Equipment used, Test methods used, Experience of supervisors, Range of organisations involved. The program outcome represents a snap shot of the competency within the industry and hence provides an overview of the industry as a whole. The more participants involved in the program then the more representative the overview Measurement Uncertainty The statistics detailed in this program do not replace the need for laboratories to separately calculated measurement uncertainties associated with each test when required by the client or NATA. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 25 of 37

26 6.1 Summary of participants results - Sample A Sample Received Damage Surface Conditioning Capping Height mm Diameter mm Weight kg Mass per unit volume kg/m 3 Maximum Force kn Compressive Strength MPa Failure Date Tested Z7 7/03/ Wet Temperate End Cut Conical F 11/03/2016 N3 8/03/ Wet Tropical Rubber Conical F 11/03/2016 R5 7/03/ moderate voids Dry Temperate Rubber Conical F 11/03/2016 V7 9/03/2016 Few small holes NR Tropical Rubber Cap Failure 14/03/2016 L6 10/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 J5 8/03/2016 Nil SS Wet Temperate Rubber Shear F 11/03/2016 V9 10/03/2016 Nil SS Wet Tropical Rubber Shear F 11/03/2016 K6 8/03/2016 Nil Dry Tropical Rubber Conical F 11/03/2016 T4 4/03/2016 NR Wet Tropical End Cut Conical F 11/03/2016 E9 4/03/2016 NR Wet Tropical End Cut Shear F 11/03/2016 S6 8/03/2016 Nil SS Wet Tropical Sulphur Conical F 11/03/2016 A3 10/03/2016 Nil Wet Tropical Rubber Conical F 11/03/2016 N2 7/03/2016 None SS Wet Tropical Rubber Abnormal SF 11/03/2016 P3 9/03/2016 None NR Temperate Rubber Conical F 11/03/2016 B8 10/03/2016 NR Wet Temperate Rubber Conical F 29/03/2016 D5 NR NR NR NR Rubber NR NR 2320 NR 39.0 Cap Failure 11/03/2016 Z2 8/03/2016 NR NR Temperate End Cut Shear F 11/03/2016 W7 8/03/2016 NA SS Wet Temperate Rubber Shear F 11/03/2016 N6 7/03/2016 Nil SS Wet Temperate End Cut Shear F 11/03/2016 S5 3/03/2016 None SS Wet Tropical Rubber Shear F 11/03/2016 P6 8/03/2016 Nil Dry Temperate Rubber Cap Failure 11/03/2016 K2 NR NR NR Temperate Rubber Conical F 14/03/2016 M4 NR Nil SS Wet Tropical End Cut Conical F 11/03/2016 X9 8/03/2016 Nil SS Wet Tropical Sulphur Conical F 11/03/2016 M6 7/03/2016 N/A SS Wet Tropical End Cut Conical F 11/03/2016 A5 7/03/2016 No Damage Wet Tropical Sulphur Conical F 11/03/2016 T8 8/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 Note: Participants weight results converted to kg where necessary. Result rejected NR = No record provided Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 26 of 37

27 6.1 Summary of participants results - Sample A - Continued Sample Received Damage Surface Conditioning Capping Height mm Diameter mm Weight kg Mass per unit volume kg/m 3 Maximum Force kn Compressive Strength MPa Failure Date Tested Q3 8/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 Y2 8/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 Z9 8/03/2016 Nil SS Wet Temperate Rubber Conical F 11/03/2016 Q8 14/03/2016 Nil Wet Temperate Sulphur Conical F 15/03/2016 J2 14/03/2016 Nil Wet Temperate Sulphur Conical F 15/03/2016 C5 12/03/2016 Nil Dry Tropical Rubber Conical F 14/03/2016 J9 10/03/2016 N/A SS Wet Tropical Rubber Conical F 11/03/2016 Q4 NR None Wet Tropical Rubber Conical F 11/03/2016 L2 7/03/2016 Nil SS Wet Tropical Rubber Conical F 11/03/2016 M8 10/03/2016 No Damage SS Wet NR Rubber Cap Failure 11/03/2016 R4 8/03/2016 Nil SS Wet Tropical Rubber Conical F 11/03/2016 B3 8/03/2016 NR SS Wet Tropical Sulphur Conical F 11/03/2016 U4 8/03/2016 Nil Dry Temperate Rubber Conical F 11/03/2016 Note: Participants weight results converted to kg where necessary. Result rejected NR = No record provided Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 27 of 37

28 6.2 Summary of participants results - Sample B Sample Received Damage Surface Conditioning Capping Height mm Diameter mm Weight kg Mass per unit volume kg/m 3 Maximum Force kn Compressive Strength MPa Failure Date Tested Z7 7/03/2016 Small chip on top Wet Temperate End Cut Conical F 11/03/2016 N3 8/03/2016 NR Wet Tropical Rubber Conical F 11/03/2016 R5 7/03/2016 minor voids Dry Temperate Rubber Conical F 11/03/2016 V7 9/03/2016 few small holes NR Tropical Rubber Shear F 14/03/2016 L6 10/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 J5 8/03/2016 Nil SS Wet Temperate Rubber Shear F 11/03/2016 V9 10/03/2016 Nil SS Wet Tropical Rubber Conical F 11/03/2016 K6 8/03/2016 Nil Dry Tropical Rubber Conical F 11/03/2016 T4 4/03/2016 defect on surface Wet Tropical End Cut Conical F 11/03/2016 E9 4/03/2016 NR Wet Tropical End Cut Conical F 11/03/2016 S6 8/03/2016 Nil SS Wet Tropical Sulphur Conical F 11/03/2016 A3 10/03/2016 Nil Wet Tropical Rubber Conical F 11/03/2016 N2 7/03/2016 None SS Wet Tropical Rubber Conical F 11/03/2016 P3 9/03/2016 None NR Temperate Rubber Conical F 11/03/2016 B8 10/03/2016 NR Wet Temperate Rubber Conical F 29/03/2016 D5 NR NR NR NR Rubber NR NR 2320 NR 42.0 Cap Failure 11/03/2016 Z2 8/03/2016 NR NR Temperate End Cut Conical F 11/03/2016 W7 8/03/2016 NR SS Wet Temperate Rubber Cap Failure 11/03/2016 N6 7/03/2016 Nil SS Wet Temperate End Cut Conical F 11/03/2016 S5 8/03/2016 None SS Wet Tropical Rubber Conical F 11/03/2016 P6 8/03/2016 Nil Dry Temperate Rubber Cap Failure 11/03/2016 K2 NR NR NR Temperate Rubber Conical F 11/03/2016 M4 NR Nil SS Wet Tropical End Cut Conical F 11/03/2016 X9 8/03/2016 Nil SS Wet Tropical Sulphur Conical F 11/03/2016 M6 7/03/2016 N/A SS Wet Tropical End Cut Conical F 11/03/2016 A5 7/03/2016 No Damage Wet Tropical Sulphur Conical F 11/03/2016 T8 8/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 Note: Participants weight results converted to kg where necessary. Result rejected NR = No record provided Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 28 of 37

29 6.2 Summary of participants results - Sample B - Continued Sample Received Damage Surface Conditioning Capping Height mm Diameter mm Weight kg Mass per unit volume kg/m 3 Maximum Force kn Compressive Strength MPa Failure Date Tested Q3 8/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 Y2 8/03/2016 Nil Wet Temperate Rubber Conical F 11/03/2016 Z9 8/03/2016 Nil SS Wet Temperate Rubber Shear F 11/03/2016 Q8 14/03/2016 Nil Wet Temperate Sulphur Shear F 15/03/2016 J2 14/03/2016 Nil Wet Temperate Sulphur Conical F 15/03/2016 C5 12/03/2016 Nil Dry Tropical Rubber Conical F 14/03/2016 J9 10/03/2016 N/A SS Wet Tropical Rubber Shear F 11/03/2016 Q4 NR None Wet Tropical Rubber Conical F 11/03/2016 L2 7/03/2016 Nil SS Wet Tropical Rubber Conical F 11/03/2016 M8 10/03/2016 No Damage SS Wet Tropical Rubber Cap Failure 11/03/2016 R4 8/03/2016 Nil SS Wet Tropical Rubber Conical F 11/03/2016 B3 8/03/2016 NR SS Wet Tropical Sulphur Conical F 11/03/2016 U4 8/03/2016 Nil Dry Temperate Rubber Cap Failure 11/03/2016 Note: Participants weight results converted to kg where necessary. Result rejected NR = No record provided Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 29 of 37

30 Appendix A - NOTES Appendix A-1 to A-4 A # in Appendix A indicates a statistically significant result where the z-score obtained is either greater than 3 or less than -3. This may be useful if it correlates with an unexpected high z score for either the mass per unit volume or compressive strength results. It is not an outlier that has to be investigated. A NR or blank entry occurs where participants did not provide a result. Minimum, Maximum and Range are calculated with outliers included. Appendix A-1: Height AS [Cl (c)] allows the height of the cylinder to be between 195 mm and 205 mm for a 100 mm diameter specimen (200 ± 5 mm). Cylinders may be rejected under AS if height is less than 189 mm, is convex by more than 5 mm or bulges greater than 5 mm etc. Appendix A-2: Average Diameter AS , Clause 6.1.2(a) indicates that the diameter of a sample at any point shall not vary from the average by more than 1 ± mm. The average of two diameter measurements is used in subsequent calculations; hence the average value of the two participant submitted diameters has been used in calculating these statistics. Appendix A-3: Weight The allowable variation in the dimension of the sample results determines the allowed variation in the volume and is partly responsible for variations in the concrete weights. Other properties of the wet concrete mix and the homogeneity of wet mix will have the greater influence on the cylinder weight obtained. Appendix A-4: Maximum Force The 'Maximum Force' value may be affected by allowable variations in the cylinder dimensions (I.e. the maximum force value does not take into account the effect of varying cross sectional areas). Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 30 of 37

31 Appendix A-1 Height : Z - Scores Test Results (mm) Z-score (Combined A & B) Test Results (mm) Z-score (Combined A & B) Sample A Sample B Sample A Sample B Sample A Sample B Sample A Sample B 1 Z J N Q R L V M L R J B V U K T S A N P B D Z N S Statistic Sample A 21 P K Number of results M Median X First Quartile M Third Quartile A IQR T Normalised IQR Q CV (%) Y Minimum Z Maximum Q Range 6 32 J C IMPORTANT : Please read Appendix A: NOTES Sample B Combined Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 31 of 37

32 Appendix A-2 Average Diameter : Z - Scores Test Results (mm) Z-score (Combined A & B) Test Results (mm) Z-score (Combined A & B) Sample A Sample B Sample A Sample B Sample A Sample B Sample A Sample B 1 Z J # 2 N Q R L V M L R J B V U K T S A N P B D Z N S Statistic Sample A 21 P K Number of results M Median X First Quartile M Third Quartile A IQR T Normalised IQR Q CV (%) Y Minimum Z Maximum Q Range J C IMPORTANT : Please read Appendix A: NOTES Sample B Combined Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 32 of 37

33 Appendix A-3 Weight : Z - Scores Test Results (kg) Z-score (Combined A & B) Test Results (kg) Z-score (Combined A & B) Sample A Sample B Sample A Sample B Sample A Sample B Sample A Sample B 1 Z J N Q R L V M L R J B V U K T S A N P B D5 NR NR Z N # S Statistic Sample A 21 P K Number of results M # Median X First Quartile M Third Quartile A IQR T Normalised IQR Q CV (%) Y Minimum Z Maximum Q Range J C IMPORTANT : Please read Appendix A: NOTES Sample B Combined Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 33 of 37

34 Appendix A-4 Maximum Force : Z - Scores Test Results (kn) Z-score (Combined A & B) Test Results (kn) Z-score (Combined A & B) Sample A Sample B Sample A Sample B Sample A Sample B Sample A Sample B 1 Z J N Q R L V M L R J B V U K T S A N P # B D5 NR NR Z N S # # Statistic Sample A 21 P K Number of results M Median X First Quartile M Third Quartile A IQR T Normalised IQR Q CV (%) Y Minimum Z # 0.56 Maximum Q Range J C IMPORTANT : Please read Appendix A: NOTES Sample B Combined Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 34 of 37

35 Appendix B LabSmart Services Concrete Compression Proficiency Program 2016 (63) INSTRUCTIONS FOR TESTER 1. Do not open the plastic bags until 11 March Store at room temperature away from fluctuating temperatures and sunlight. 2. Please read these instructions carefully. 3. Please check that the package you have received contains the following: Results Log Two nominal 100 mm Ø by 200 mm concrete cylinders sealed in plastic bags marked Sample A and Sample B. 4. Inspect packaging on arrival for damage or leakage. Contact LabSmart Services if box is wet or damaged or anything is missing (Phone ) 5. It is strongly recommended that participants follow AS 1012, Method 9 when testing the concrete cylinders but an alternative equivalent method may also be used. 6. On 11 th March remove each cylinder from the plastic bag. Remove newspaper covering. Inspect each cylinder and record its condition on the proficiency testing results log sheet (AS 1012, clause 4.1 (a) to (h)). If cylinders show any chipping or damage please contact LabSmart Services before testing. Air bubbles are expected. 7. Within 10 minutes of opening the plastic bag immerse each concrete cylinder into the curing tank. Allow the cylinders to pre-condition for at least three hours prior to capping and testing by full immersion in water at 23 ± 2 o C temperate zone or 27 ± 2 o C tropical zone. 8. Follow AS 1012, Method 9. Test both cylinders within 15 minutes of each other. 9. Record all information and calculations as per AS 1012, Method 9 on the proficiency testing results log sheet but to the accuracy shown on the results log sheet. 10. Ensure to have the Laboratory Supervisor check & approve then sign the log sheet. 11. Please fax or the Results Log to LabSmart Services by 18 March Fax: (03) OR petery@labsmartservices.com.au 12. Please retain the completed Results Log as this contains your participation code that will identify your results in the technical report covering the proficiency testing program. It is also recommended that a copy of completed worksheets be kept with the results log in your proficiency file. 13. Have a query? Contact Peter at LabSmart Services. Phone Thank you for participating in this proficiency testing program. Copyright: LabSmart Services Pty Ltd Report V1 - June 2016 Page 35 of 37 PT Instructions V1.7 (63)-Appendix B.docx